Periodic solutions of autonomous $S^1$-symmetric Newtonian systems
The aim of this paper is to formulate necessary conditions and sufficient ones for the existence of closed connected sets of nonstationary $2 π$-periodic solutions of $S^1$-symmetric Newtonian systems in $C_{2 π}([0,2π],Ω) \times (0,+ \infty)$. As the main topological tool we apply the degree for equivariant gradient maps.
math.DS↗